I have a facebook rep for my advertising account, and I was talking about reddit with him. I asked if he would be open to answering some questions from the community about best practices, how the algorithims work, and whatever questions you might have. He obviously can't answer every question but he said he would try to answer as many as possible.

If you would be interested in this just comment saying you are.

Edit: Based on the comments I think enough interest has been shown. I'll see when we get this going.

Agree, that would definitely contribute. However, we almost always have Adwords Search and Fb ads on at the same time. Wouldn't Adwords clicks also be ~3x GA sessions? For us, Aw and GA are always 10-20% variance.